Treatment of chronic dermal ulcers is a significant problem that confounds many clinicians. This application examines the ability of a keratinocyte-populated microcarrier device (KPMB-device; patent no. 5,972,332) to modify the wound fluid environment into which it is placed and thereby enhance healing. The device consists of human keratinocytes grown on cell microcarrier beads placed into porous fabric bags. These bags can be placed into wounds and later retrieved. We hypothesize that modifying the wound environment to produce a milieu more compatible for host cells will promote healing of chronic wounds. The research will examine the ability of the device of modify wound fluid and relate these changes to the ability of the device to enhance wound healing. Determination of the expression and secretion of growth factors, protease inhibitors, and an extracellular matrix protein by the device keratinocytes will be performed to identify a marker molecule(s) of device activity. The ability of the KPMB-devices to modify wound fluid will be assessed focusing on changes in the level product release assay and to identify further manipulations of the KPMB-device to optimize the healing produced by these devices.